U.S. patent application number 17/101859 was filed with the patent office on 2021-07-01 for cam device, work supply device and separating device.
This patent application is currently assigned to KOYO MACHINE INDUSTRIES CO., LTD.. The applicant listed for this patent is KOYO MACHINE INDUSTRIES CO., LTD.. Invention is credited to Hideto KITATSUJI, Tsutomu TOKUMOTO.
Application Number | 20210197333 17/101859 |
Document ID | / |
Family ID | 1000005273065 |
Filed Date | 2021-07-01 |
United States Patent
Application |
20210197333 |
Kind Code |
A1 |
KITATSUJI; Hideto ; et
al. |
July 1, 2021 |
CAM DEVICE, WORK SUPPLY DEVICE AND SEPARATING DEVICE
Abstract
A cam device includes a drive cam, a follower, a holding cam,
and a restriction roller. The drive cam reciprocally rotates. The
follower intermittently reciprocate linearly by the drive cam. The
holding cam is rotationally driven integrally with the drive cam.
The restriction roller is provided on the follower and restricts a
movement of the follower by coming in contact with the holding cam.
The holding cam separates from the restriction roller and the
holding cam is in a holding release state, when the drive cam is in
an engaged state with the follower.
Inventors: |
KITATSUJI; Hideto; (Osaka,
JP) ; TOKUMOTO; Tsutomu; (Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOYO MACHINE INDUSTRIES CO., LTD. |
Osaka |
|
JP |
|
|
Assignee: |
KOYO MACHINE INDUSTRIES CO.,
LTD.
Osaka
JP
|
Family ID: |
1000005273065 |
Appl. No.: |
17/101859 |
Filed: |
November 23, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23Q 7/04 20130101; F16H
53/06 20130101; F16H 25/18 20130101 |
International
Class: |
B23Q 7/04 20060101
B23Q007/04; F16H 53/06 20060101 F16H053/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 26, 2019 |
JP |
2019-235767 |
Claims
1. A cam device configured to convert a rotational movement of a
drive unit to a linear movement on a driven side, the cam device
comprising: a drive cam configured to be driven by the drive unit
and to reciprocally rotate in forward and reverse directions within
a predetermined angle range around a rotation axis; a first
follower configured to intermittently reciprocate linearly by the
drive cam; a second follower configured to intermittently
reciprocate linearly by the drive cam; a holding cam configured to
be rotationally driven integrally with a rotational reciprocating
movement of the drive cam about the rotation axis, the holding cam
having an arcuate outer peripheral surface which is discontinuous
on a side facing the drive cam; a first restriction roller provided
on the first follower and configured to restrict a movement of the
first follower by coming in contact with the holding cam; and a
second restriction roller provided on the second follower and
configured to restrict a movement of the second follower by coming
in contact with the holding cam, wherein the first follower and the
second follower are arranged to be capable of moving linearly at
opposite positions on both sides of a rotation axis of the drive
cam, and wherein the first follower and the second follower are
capable of being cam-engaged with the driven cam alternatively and
independently of each other, and configured such that when the
drive cam is in an engaged state with the first follower, the drive
cam is in an engagement release state with the second follower and
the holding cam comes into contact with the second restriction
roller to hold the second follower at a predetermined position and
the holding cam is separated from the first restriction roller and
is in a holding release state with the first follower, and when the
drive cam is in an engaged state with the second follower, the
drive cam is in an engagement release state with the first follower
and the holding cam comes into contact with the first restriction
roller to hold the first follower at a predetermined position and
the holding cam is separated from the second restriction roller and
is in a holding release state with the second follower.
2. The cam device according to claim 1, wherein the first follower
and the second follower are configured not to be biased in a linear
movement direction by the biasing member.
3. The cam device according to claim 1, further comprising: an
outer holding cam formed in a radially outer side of the holding
cam, the outer holding cam having an arcuate inner peripheral
surface which is concentric with the holding cam, wherein the outer
holding cam and the holding cam are configured to restrict the
first follower or the second follower on a standby side from moving
in a vertical direction by the first restriction roller or the
second restriction roller.
4. A work supply device comprising: the cam device according to
claim 1, wherein the first follower and the second follower
respectively include arms having work chucks, and wherein the first
follower and the second follower are configured to handle works
gripped by the work chucks.
5. The work supply device according to claim 4, wherein a plurality
of drive cams are reciprocally rotated about a common rotation axis
and a plurality of pairs of first follower and second follower are
linearly reciprocated.
6. A cam device configured to convert a rotational movement of a
drive unit to a linear movement on a driven side, the cam device
comprising: a drive cam configured to be driven by the drive unit
and to reciprocally rotate in forward and reverse directions within
a predetermined angle range around a rotation axis; a follower
configured to intermittently reciprocate linearly by the drive cam;
a holding cam configured to be rotationally driven integrally with
a rotational reciprocating movement of the drive cam about the
rotation axis, the holding cam having an arcuate outer peripheral
surface which is discontinuous on a side facing the drive cam; and
a restriction roller provided on the follower and configured to
restrict a movement of the follower by coming in contact with the
holding cam, wherein the follower is arranged to be linearly
movable at a position apart from a rotation center of the drive cam
by a predetermined distance, and wherein the follower is configured
to be cam-engaged with the drive cam, so that the holding cam
separates from the restriction roller and the holding cam is in a
holding release state when the drive cam is in an engaged state
with the follower.
7. The cam device according to claim 6, wherein the follower forms
a part of a pallet, and wherein the pallet is configured to be
transferred in a feeding direction by the drive cam.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority from
Japanese Patent Application No. 2019-235767 filed on Dec. 26, 2019,
the contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a cam device for
converting a rotational movement of a drive unit into a linear
movement on a driven side, a work supply device including the cam
device, and a separating device including the cam device.
BACKGROUND ART
[0003] JP2002-130421A discloses a type of a cam device of related
art. The cam device of the related art includes a drive cam, a
first driven cam and a second driven cam. The drive cam
reciprocally rotates in forward and reverse directions within a
predetermined angle range. The first and second driven cams
intermittently reciprocate linearly by the reciprocal rotation of
the drive cam.
[0004] As illustrated in FIG. 12, in the cam device 601 of the
related art, the driven cams 606a and 607a are arranged to be
linearly movable parallel to each other at opposite positions on
both sides of a rotation center of the drive cam 605. The driven
cams 606a and 607a can be cam-engaged with the drive cam 605,
respectively.
[0005] In the cam device 601, the elastic force of a spring 621 is
used to hold an arm (arm 606 in a timing of FIG. 12) on a standby
side at a top end. Arms 606 and 607 include vertical holes 621a and
the springs 621 are inserted therein. An upper end of the hole 621a
is closed by an upper spring receiver 628 and the arms 606 and 607
are supported by receiving the upward elastic forces of the springs
621. Lower ends of the springs 621 are supported by lower spring
receivers 623 which can move up and down in the holes 621a of the
arms 606 and 607 and the lower spring receiver 623 is supported by
an adjusting bolt 622 from below. The adjusting bolt 622 extends
downward through an opening on a lower surface of the arm and is
supported by a bracket 625 provided at a lower end of a base 612.
The adjusting bolt 622 is a screw adjusting type and the elastic
force of the spring 621 is adjusted by moving the lower spring
receiver 623 up and down. Upper stoppers 624 are attached to the
base 612 above the arms 606 and 607. As illustrated in FIG. 13, the
standby side arm 606 lifted upward by the spring 621 is held at the
top end position. In such a structure, the spring 621 is compressed
each time the arms 606 and 607 descend.
[0006] In the cam device of the related art, the spring may have a
short life of two to three years, because the spring may be broken
due to repeated compression load. In addition, according to the cam
device of the related art, it would be necessary to adjust an
elastic force of the spring. In addition, there would be
restrictions on weights of attachments such as chucks and weights
of works to be transferred, because a support rigidity of the arm
on the standby side is low. Moreover, since the spring is
compressed when the arm descends, energy loss would be large.
Furthermore, the device may have to be assembled against an elastic
force of the spring.
SUMMARY
[0007] The present disclosure relates to a cam mechanism capable of
converting a rotational movement into a linear movement with a
simple structure.
[0008] According to the present disclosure, a cam device includes a
drive cam, a follower, a holding cam, and a restriction roller. The
drive cam reciprocally rotates. The follower intermittently
reciprocate linearly by the drive cam. The holding cam is
rotationally driven integrally with the drive cam. The restriction
roller is provided on the follower and restricts a movement of the
follower by coming in contact with the holding cam. The holding cam
separates from the restriction roller and the holding cam is in a
holding release state, when the drive cam is in an engaged state
with the follower.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1A is a front view of a cam device according to an
embodiment.
[0010] FIG. 1B is a side view of the cam device according to the
embodiment.
[0011] FIG. 2A is a front view of the cam device in a standby
position.
[0012] FIG. 2B is a front view of the cam device in a state where a
second arm descends.
[0013] FIG. 3A is a front view of the cam device in a state where a
first arm is at a bottom end.
[0014] FIG. 3B is a front view of the cam device in a state where a
drive cam is switched to the first arm.
[0015] FIG. 3C is a front view of the cam device in a state where
the first and second arms are at their top ends and a drive cam is
at a neutral position.
[0016] FIG. 3D is a front view of the cam device in a state where
the drive cam is switched to the second arm.
[0017] FIG. 3E is a front view of the cam device in a state where
the second arm is at a bottom end.
[0018] FIG. 4A is a plan view of a cam disc including the drive cam
and a holding cam.
[0019] FIG. 4B is a front view of the cam disc.
[0020] FIG. 4C is a side view of the cam disc.
[0021] FIG. 5A is a rear view of the cam device in an unprocessed
work passing process of a work supply/discharge cycle.
[0022] FIG. 5B is a rear view of the cam device in a processed work
removal process.
[0023] FIG. 5C is a rear view of the cam device in an unprocessed
work loading process.
[0024] FIG. 5D is a rear view of the cam device in a processed work
passing process.
[0025] FIG. 5E is a plan view of the cam device illustrating an
outline of the work supply/discharge cycle.
[0026] FIG. 6 is a perspective view illustrating an outline of a
cam device according to a first modification example of a first
embodiment.
[0027] FIG. 7 is a front view illustrating an outline of a cam
device according to a second modification example of the first
embodiment.
[0028] FIG. 8 is a front view illustrating an outline of a cam
device according to a third modification example of the first
embodiment.
[0029] FIG. 9 is a plan view illustrating an outline of a cam
device according to a second embodiment.
[0030] FIG. 10A is a plan view of the cam device according to the
second embodiment in a standby state.
[0031] FIG. 10B is a plan view of the cam device according to the
second embodiment in a pallet capturing state.
[0032] FIG. 10C is a plan view of the cam device according to the
second embodiment in a feeding speed control state.
[0033] FIG. 10D is a plan view of the cam device according to the
second embodiment in a feeding and next pallet capturing state.
[0034] FIG. 11 is a front view illustrating an outline of a cam
device according to a modification example of the second
embodiment.
[0035] FIG. 12 is a front view illustrating a cam device of the
related art.
[0036] FIG. 13 is an enlarged front view illustrating an outline of
an operation of the cam device of the related art.
DESCRIPTION OF EMBODIMENTS
[0037] Embodiments will be described below with reference to the
drawings.
First Embodiment
[0038] Configuration of Cam Device
[0039] FIGS. 1A to 3E illustrate a cam device 1 according to a
first embodiment. The cam device 1 converts a rotational motion of
a drive unit into a linear motion on a driven side. Specifically,
the cam device 1 forms, for example, a main part of a work supply
device 3 of a vertical double disk surface grinder 2 shown in FIGS.
5A to 5E.
[0040] The cam device 1 mainly includes a drive cam 5 and a pair of
first and second arms 6 and 7. The drive cam 5 reciprocally rotates
in forward and reverse directions within a predetermined angle
range. The pair of first and second arms 6 and 7, as a first
follower and a second follower, intermittently reciprocate linearly
by the reciprocating rotation of the drive cam 5.
[0041] As illustrated in FIGS. 4A to 4C, the cam device 1 includes
a cam disk 9 and a cylindrical cam roller 5a. The cam disk 9 is a
rotating disk which is supported so as to be rotatable in the
forward and reverse directions about a rotation center, that is, a
rotation axis 10. The cylindrical cam roller 5a forming the drive
cam 5 is rotatably supported on an outer peripheral edge portion
which is apart from the rotation axis 10 by a predetermined
distance. In the illustrated embodiment, a horizontally extending
rotation axis 10 of the cam disk 9 is rotatably supported at the
center of the upper part of a frame-shaped device body 12. The
rotation axis 10 is drivingly connected to a drive device 13 as a
drive unit which is a rotary drive source.
[0042] The drive device 13 includes a servo motor 14 as a main
part. The servo motor 14 is provided in the device body 12. An
output shaft of the servo motor 14 is connected to the rotation
axis 10 of the cam disk 9 via a worm reducer 15. Therefore, when
the servo motor 14 is driven to rotate in the forward and reverse
directions, the rotation is transmitted to the rotation axis 10
through the worm reducer 15, and then the cam disk 9 reciprocatedly
rotates in the forward and reverse directions by an amount
corresponding to the rotation amount of the servo motor 14. The
worm reducer 15 may be omitted.
[0043] As illustrated in FIGS. 4A to 4C, the cam roller 5a is
rotatably supported by the cam disk 9 about a roller shaft 5b made
of a bolt or the like. The cam roller 5a forms a main part of the
drive cam 5. A neutral position is defined to a situation when the
cam roller 5a positions vertically above the center of rotation of
the cam disk 9. Depending on purposes, the cam roller may have a
structure in which a cylindrical cam shaft member is integrally
fixed to the drive cam 5, in addition to the freely rotatable cam
roller 5a as illustrated in FIGS. 4A to 4C. By configuring the
drive cam 5 with the rotatable cam roller 5a, it is possible to
reduce problems such as abrasion, seizure, and kinking due to
friction.
[0044] The cam disk 9 includes a holding cam 8 which is
rotationally driven integrally about the rotation axis 10 together
with the reciprocating rotation of the drive cam 5. The holding cam
8 can hold the first and second arms 6 and 7 at a top end. The
holding cam 8 includes an arcuate rib having an arcuate outer
peripheral surface discontinuous on a side facing the drive cam 5.
The arcuate outer peripheral surface has a center on the rotation
axis 10 of the cam disk 9. For example, as illustrated in FIG. 4B,
an opening 8a is formed on a side of the drive cam 5 over a
predetermined rotation range (angle .alpha.), and the arcuate rib
projects in a C-shape when viewed from the front. The holding cam 8
may have at least an arcuate outer peripheral surface and is not
necessarily to be the arcuate rib.
[0045] As illustrated in FIGS. 1A and 1B, the first and second arms
6 and 7 having the same symmetrical structure are provided in
parallel with each other. The first and second arms 6 and 7 are
respectively attached to a pair of guide rails 20 provided in
parallel on the device body 12 and configured to be linearly guided
in a vertical direction. The first and second arms 6 and 7 do not
necessarily have to be parallel to each other and may be inclined
with respect to each other. As illustrated in FIG. 1B, a chuck 50
for holding a work W is provided on each of the first and second
arms 6 and 7 via a chuck mounting bracket 51 extending in a
horizontal direction. In the embodiment, two chucks 50 are provided
on one arm, but only one chuck may be provided, or three or more
chucks may be provided. The chucks 50 provided on the first and
second arms 6 and 7 have, for example, opening/closing chuck claws
50a which are appropriately opened or closed by an air cylinder.
These chuck claws 50a direct vertically downward. The chuck 50 may
be a vacuum suction type. The chuck claws 50a do not have to direct
vertically downward, but may direct horizontally. In FIG. 1A, the
chuck 50 and the chuck mounting bracket 51 are not illustrated for
simplification.
[0046] The first arm 6 includes a slide body 16 which is provided
in the device body 12 vertically slidably by a slide mechanism 17.
The upper part of the slide body 16 forms a follower which is
disengageably engaged with the cam roller 5a of the drive cam 5.
Specifically, the slide body 16 includes guide members 17a and 17b
(see FIG. 1B) fixedly mounted on the upper and lower portions of a
back surface of the slide body 16. The guide members 17a and 17b
are slidable along the guide rail 20 provided in the device body 12
to extend linearly in the vertical direction. That is, the guide
members 17a and 17b and the guide rail 20 form the slide mechanism
17. The slide mechanism 17 allows the slide body 16 to smoothly
slide in the vertical direction in a stable state.
[0047] The first arm 6 includes upper and lower pieces 6a and 6b
provided on a support bracket 19. The upper and lower pieces 6a and
6b are vertically separated at a predetermined interval. The
support bracket 19 is mounted and fixed on the upper end of the
slide body 16 in a side of the cam disk 9. The upper and lower
pieces 6a and 6b are arranged while considering the shape and
dimensions of the cam roller 5a, the rotation path, and the like,
so that the cam roller 5a of the drive cam 5 is slidably and
disengageably engaged with an engagement groove 6c formed
therebetween. Similarly, the second arm 7 includes upper and lower
pieces 7a and 7b provided on a support bracket 19. The upper and
lower pieces 7a and 7b are vertically separated at a predetermined
interval. The support bracket 19 is mounted and fixed on the upper
end of the slide body 16 in a side of the cam disk 9. The upper and
lower pieces 7a and 7b are arranged while considering the shape and
dimensions of the cam roller 5a, the rotation path, and the like,
so that the cam roller 5a of the drive cam 5 is slidably and
disengageably engaged with an engagement groove 7c formed
therebetween.
[0048] The first arm 6 includes a first restriction roller 21. The
first restriction roller 21 restricts the movement of the first arm
6 by coming into contact with the arcuate outer peripheral surface
of the holding cam 8. The second arm 7 includes a second
restriction roller 22. The second restriction roller 22 restricts
the movement of the second arm 7 by coming into contact with the
arcuate outer peripheral surface of the holding cam 8. In other
words, the holding cam 8 is configured to support the first
restriction roller 21 or the second restriction roller 22 from
below within a predetermined rotation range of the cam disk 9 to
support the first arm 6 or the second arm 7 at the top end.
[0049] By configuring the first restriction roller 21 and the
second restriction roller 22 as rotatable rollers, problems such as
abrasion, seizure, and kinking due to friction can be reduced. The
cut-out range (angle c) of the opening 8a of the above holding cam
8 is set such that the first restriction roller 21 or the second
restriction roller 22 of the arm on the rotation direction side of
the cam disk 9 is released from the holding cam 8 when the cam disk
9 starts rotating.
[0050] As a result, the first and second arms 6 and 7 can be
cam-engaged with the drive cam 5 alternately continuous and
independently of each other. That is, when the drive cam 5 is in an
engagement state with the first arm 6, the drive cam 5 is in an
engagement release state with the second arm 7 and the holding cam
8 comes into contact with the second restriction roller 22 to hold
the second arm 7 in a predetermined position, while the holding cam
8 is separated from the first restriction roller 21 and is in a
holding release state. In addition, when the drive cam 5 is in an
engagement state with the second arm 7, the drive cam 5 is in an
engagement release state with the first arm 6 and the holding cam 8
comes into contact with the first restriction roller 21 to hold the
first arm 6 at a predetermined position, while the holding cam 8 is
separated from the second restriction roller 22 and is in a holding
release state. By providing the holding cam 8, it is not necessary
for the first and second arms 6 and 7 to be biased in the linear
movement direction by the biasing member, and the own weights of
the first and second arms 6 and 7 are configured to be held by the
holding cam 8. A lifting stroke S of the first and second arms 6
and 7 is determined by the radius of rotation of the drive cam 5
and the rotation angle of the cam disk 9. The lifting speed is
determined by the rotation speed of the cam disk 9. The speed can
be set freely depending on situations including whether the arm is
descending or ascending, and whether the work is held or not. Which
of the first and second arms 6 and 7 is driven can be switched
depending on whether the drive cam 5 rotates left or right from the
neutral position. The arm on a side opposite to the arm which is
moving up or down is held at the top end, that is, the standby
position because the first restriction roller 21 or the second
restriction roller 22 continues to be supported at a fixed position
by the holding cam 8.
[0051] In FIG. 1A, a cam stopper 11 capable of abutting on the cam
roller 5a is provided at a position corresponding to the lower part
of the cam disk 9 of the device body 12. A screw-type lower stopper
23 which abuts and engages with the lower end of the slide body 16
is provided on the lower portion of the device body 12. Similarly,
a screw-type upper stopper 24 which abuts and engages with the
upper end of the slide body 16 is provided on the upper portion of
the device body 12. However, the stoppers 11, 23, and 24 are not
for abutting on the first and second arms 6 and 7 or the cam disk 9
to determine the stroke S, but are provided for preparing for a
case where the drive cam 5 breaks or the servo motor 14 fails.
Proximity sensors 25 for the first and second arms 6 and 7 are
provided at the upper ends of the device body 12. By detecting the
first and second arms 6 and 7 with those proximity sensors 25, it
is configured to determine that the first and second arms 6 and 7
have been elevated to a linear movement initial position U (shown
in FIG. 1B and the like).
[0052] Configuration of Work Supply Device
[0053] Next, the configuration of the work supply device 3
including the cam device 1 will be specifically described. As
illustrated in FIGS. 5A to 5E, the work supply device 3 includes
the cam device 1 as a drive device for a loading unit 35 which
supplies the work W to the surface grinder 2 and an unloading unit
36 which discharges the work W. FIG. 5A is a rear view and the rear
side of the cam device 1 is not illustrated in detail for easy
viewing.
[0054] As illustrated in FIG. 5E, the surface grinder 2 is a
vertical double disk type equipped with a pair of upper and lower
grinding wheels 26 and 27 for simultaneously grinding the upper and
lower surfaces of the work W (the drawing illustrates only the
grinding wheel 27 on the lower side). Both of those grinding wheels
26 and 27 are arranged to be rotatably driven in the upper and
lower positions with the height of the work W interposed
therebetween. A carrier 56 is provided to be horizontally movable.
The carrier 56 loads and unloads the work W between a work
supply/discharge position P2 on a bed 55 and the grinding wheels 26
and 27.
[0055] The carrier 56 is structured to be rotated or swung about a
central axis 56a. Work pockets 56b into which the work W can be
inserted and held in the vertical direction are formed at both ends
of the carrier 56. By the rotation or swing of the carrier 56, the
works W in the work pockets 56b at both ends of the carrier 56 is
configured to be horizontally reciprocally rotated by 180.degree.
between the work supply/discharge position P2 and a processing
position between the grinding wheels 26 and 27.
[0056] A carry-in conveyor 30 and a carry-out conveyor 31 are used
for carrying the work W into and out of the surface grinder 2
through the work supply device 3 and are composed of belt conveyor
devices, for example. Belt transfer surfaces 30a and 31a of the two
conveyors 30 and 31 are positioned at substantially the same height
as the work supply/discharge position P2 on the bed 55. The front
end portion of the carry-in conveyor 30 and the rear end portion of
the carry-out conveyor 31 are respectively set to a work carry-in
position P1 and a work carry-out position P3. The transfer devices
30 and 31 at the entrance and exit are not particularly limited to
conveyors, shuttles, robots, or the likes, as long as they can
carry the works W in and out at the delivery position. Even when
the transfer direction of the work W is opposite to (from right to
left) that in FIG. 5A, an operation can be done by simply reversing
the movement of the device left and right.
[0057] As illustrated in FIG. 1B, the work supply device 3 is
provided on a device base 40 provided on a side of the surface
grinder 2 so that the cam device 1 described above can be
horizontally moved via a horizontal movement device 41.
[0058] The horizontal movement device 41 includes a pair of upper
and lower moving rails 42 extending horizontally in the device base
40 on the fixed side. Moving guides 43 attached and fixed to the
work supply device 3 on the movable side are provided to be able to
move on the moving rails 42. The horizontal movement device 41 also
includes a drive source 44 for moving the work supply device 3 in
the horizontal direction is provided. Although not specifically
illustrated, the drive source 44 includes a ball screw mechanism
44a and a servo motor (not illustrated). The ball screw mechanism
44a is provided to extend in parallel with the moving rail 42
between the work supply device 3 and the moving rail 42. The servo
motor rotationally drives the ball screw mechanism 44a.
[0059] By the horizontal movement device 41, as illustrated in FIG.
5E, the loading unit 35 and the unloading unit 36 of the work
supply device 3 are configured to horizontally move and stop
positioning between the work carry-in position P1, the work
supply/discharge position P2 of the surface grinder 2, and the work
carry-out position P3. In the work carry-in position P1, the work W
is carried in by the carry-in conveyor 30. In the work carry-out
position P3, the work W is carried out by the carry-out conveyor
31. The work carry-in position P1, the work supply/discharge
position P2, and the work carry-out position P3 are arranged
horizontally.
[0060] In the illustrated embodiment, the second arm 7 of the cam
device 1 forms the actuator of the loading unit 35 of the work
supply device 3, while the first arm 6 forms the actuator of the
unloading unit 36.
[0061] Then, the work supply device 3 is horizontally moved by the
horizontal movement device 41 and either one of the loading unit 35
and the unloading unit 36 of the work supply device 3 is positioned
at the work carry-in position P1, the work supply/discharge
position P2, and the work carry-out position P3. At each of those
positions P1, P2, and P3, a lifting movement (reciprocating linear
movement) is made between (movement stroke S) an standby position U
which is the top dead center (that is, the linear movement initial
position) and an operation position D which is the bottom dead
center, in such a manner that it is configured to be
drive-controlled to perform a chucking operation.
[0062] Operation of Cam Device
[0063] Next, the operation of the cam device 1 described above will
be described.
[0064] In the embodiment, as illustrated in FIGS. 1A and 1B, the
state in which the cam roller 5a is at the uppermost position is
set as the neutral reference position. As illustrated in FIG. 3C,
when the cam disk 9 is in the neutral position, the holding cam 8
engages with the first and second restriction rollers 21 and 22 and
both the first and second arms 6 and 7 are held at the top end,
that is, the standby position.
[0065] First, the case of raising and lowering the first arm 6 will
be described. When the cam disk 9 starts rotating to the left from
the neutral position, as illustrated in FIG. 3B, the cam roller 5a
of the cam disk 9 engages with the engagement groove 6c between the
upper and lower pieces 6a and 6b of the first arm 6. Almost at the
same time, the contact between the holding cam 8 of the cam disk 9
and the first restriction roller 21 of the first arm 6 are
released.
[0066] Next, as illustrated in FIG. 3A, the first arm 6 descends to
a predetermined position as the cam disk 9 rotates.
[0067] Next, when the cam disk 9 starts rotating in the opposite
direction (to the right), the first arm 6 starts rising.
[0068] After that, as illustrated in FIG. 3C, when the cam disk 9
rotates to the neutral position, the restriction roller 21 of the
first arm 6 comes into contact with the outer peripheral surface of
the holding cam 8 and the first arm 6 is held at the top end. As a
result, the lifting operation of the first arm 6 for one stroke S
is performed.
[0069] Next, the case of raising and lowering the second arm 7 will
be described. First, when the cam disk 9 starts rotating to the
right from the neutral position, as illustrated in FIG. 3D, the cam
roller 5a of the cam disk 9 engages with the engagement groove 7c
between the upper and lower pieces 7a and 7b of the second arm 7.
Almost at the same time, the contact between the outer peripheral
surface of the holding cam 8 of the cam disk 9 and the second
restriction roller 22 of the second arm 7 is released.
[0070] Next, as illustrated in FIG. 3E, the second arm 7 descends
to a predetermined position as the cam disk 9 rotates.
[0071] Next, when the cam disk 9 starts rotating in the opposite
direction (to the left), the second arm 7 starts rising.
[0072] After that, as illustrated in FIG. 3C, when the cam disk 9
rotates to the neutral position, the second restriction roller 22
of the second arm 7 comes into contact with the outer peripheral
surface of the holding cam 8 and the second arm 7 is held at the
top end. As a result, the lifting operation of the second arm 7 for
one stroke S is performed.
[0073] The lifting stroke S of the first and second arms 6 and 7
can be appropriately set by adjusting the rotation angle of the
drive cam 5 within the range of the above semicircular orbit.
[0074] In the cam device 1, the drive cam 5 is alternately
reciprocally rotation-controlled to the first arm 6 side and the
second arm 7 side in FIG. 1A by the servo motor 14 so that the
steps described above are repeated and the first and second arms 6
and 7 intermittently perform reciprocating linear motions (vertical
lifting movements in the present embodiment). Thus, in the present
embodiment, it is not necessary to provide a spring 621 as
illustrated in FIGS. 12 and 13 and the holding cam 8 does not cause
the first arm 6 and the second arm 7 to drop, so that the first arm
6 and the second arm 7 continue to be supported in a fixed
position.
[0075] Supplying and Discharging Work W by Work Supply Device
[0076] In the surface grinder 2 configured as described above,
supply and discharge operations of the work W by the work supply
device 3 are performed as follows.
[0077] (Step S01) In a delivery process of the unprocessed work, as
illustrated in FIG. 5A, in the work supply device 3, the loading
unit 35 is positioned at the work carry-in position P1 of the
carry-in conveyor 30 and the second arm 7 grabs the unprocessed
work W that has been carried to the work carry-in position P1. That
is, the second arm 7 of the loading unit 35 descends from the
standby position U to the operation position D by the cam operation
of the cam device 1 described above and the chuck claw 50a of the
chuck 50 grabs and holds the work W at the work carry-in position
P1. Then, the second arm 7 ascends and returns from the operation
position D to the standby position U by the cam operation of the
cam device 1 described above.
[0078] (Step S02) In a removal process of the processed work, the
work supply device 3 horizontally moves toward the work carry-out
position P3 and the unloading unit 36 is positioned at the work
supply/discharge position P2 of the surface grinder 2. Then, as
illustrated in FIG. 5B, the first arm 6 grasps the processed work W
discharged to the work supply/discharge position P2. That is, the
first arm 6 of the unloading unit 36 descends from the standby
position U to the operation position D by the cam operation of the
cam device 1 described above and the chuck claw 50a of the chuck 50
grabs and holds the processed work W in the work pocket 56b of the
carrier 56 which is stopped and waiting at the work
supply/discharge position P2. Then, the first arm 6 ascends and
returns from the operation position D to the standby position U by
the cam operation of the cam device 1 described above.
[0079] (Step S03) In a loading process of the unprocessed work, as
illustrated in FIG. 5C, the work supply device 3 moves horizontally
toward the work carry-out position P3 again and the loading unit 35
is positioned at the work supply/discharge position P2. Then, the
second arm 7 places and supplies the unprocessed work W to the work
supply/discharge position P2. That is, similar to Step S01, the
second arm 7 of the loading unit 35 descends from the standby
position U to the operation position D and the chuck claw 50a of
the chuck 50 releases the held work W and places the work W in the
empty work pocket 56b of the carrier 56, which stands by on the
work supply/discharge position P2. Then, the second arm 7 ascends
and returns from operation position D to the standby position U
again.
[0080] (Step S04) In the delivery process of the processed work, as
illustrated in FIG. 5D, the work supply device 3 moves horizontally
toward the work carry-out position P3 again and the unloading unit
36 is positioned at the work carry-out position P3 of the carry-out
conveyor (unloading device) 31, and then by the cam operation of
the cam device 1, the first arm 6 descends from the standby
position U to the operation position D and the chuck claw 50a of
the chuck 50 places the processed work W, which has been held, on
the work carry-out position P3. Next, the first arm 6 ascends and
returns to the standby position U.
[0081] (Step S05) The work supply device 3 horizontally moves to
the left (returning direction) in FIG. 5A to return to the work
carry-in position P1, and thereafter, the steps S01 to S04 are
sequentially repeated. On the other hand, in step S03, the
unprocessed work W supplied to the work supply/discharge position
P2 is moved to the processing position between the grinding wheels
26 and 27 by the rotation or swing of the carrier 56, as
illustrated in FIG. 5E, and surface grinding is performed on the
upper and lower surfaces by the grinding wheels 26 and 27 which are
rotationally driven. The work W that has completed grinding is
discharged to the work supply/discharge position P2 by the rotation
or swing of the carrier 56 again and is carried out to the
carry-out conveyor 31 in Step S02.
[0082] As described above, in the cam device 1 according to the
embodiment, by adopting the structure in which the pair of first
and second arms 6 and 7 linearly operates by the single drive cam
5, the operating regions of the first and second arms 6 and 7 are
almost the same as the lifting stroke S of the drive cam 5.
Therefore, the device structure of the cam device 1 can be
downsized and simplified. As a result, the operating areas of the
loading unit 35 and the unloading unit 36 of the work supply device
3 may be small and the work supply device 3 can be downsized and
simplified to reduce the installation space. The drive source of
the first and second arms 6 and 7 of the loading unit 35 and the
unloading unit 36 is a single shared source, and in such viewpoint
as well, the work supply device 3 can be downsized and the device
cost can be reduced. In addition, the drive control of the first
and second arms 6 and 7 is also mechanically synchronized and the
control system can be simplified.
[0083] As described above, in the embodiment, by rotating the drive
cam 5, the rotational movement is surely converted into the linear
movements of the first and second arms 6 and 7. The arm opposite to
the arm in linear motion continues to be held in the fixed position
by the holding cam 8. Then, when the drive cam 5 is brought into
the engaged state, the corresponding restriction roller is
separated from the holding cam 8 and is brought into the holding
release state, so that the linear movement of the arm is possible
according to the operation of the drive cam 5. Therefore, it is not
necessary to bias the arm with the spring 621 to hold the arm in a
fixed position as in the case of the related art illustrated in
FIGS. 12 and 13. As a result, the number of parts is reduced to
facilitate the assembly and the energy loss generated when
compressing the spring 621 is reduced, and further the maintenance
work due to the deterioration of the spring 621 is reduced. The
trouble of fine adjustment of the biasing force of the spring 621
can also be saved.
[0084] Therefore, according to the cam device 1 of the embodiment,
it is possible to realize a cam mechanism capable of converting the
rotational movement into the linear movement with a simple
structure. The cam device 1 includes fewer components than the one
including the spring 621 as in the related art in FIGS. 12 and 13,
is easy to assemble and adjust, and is space-saving, lightweight,
and low-cost. The cam device 1 only needs to control the rotation
direction and speed of the cam disk 9 and the electric control
system is simple, low cost and energy saving. Since the cam device
1 is a positive cam drive, the cam device 1 has high reliability,
high rigidity and high accuracy, and a long life.
[0085] Although not illustrated, the arm on the standby side can be
pulled out upward while the other arm is moving up and down. By
rotating the cam disk 9 by 180.degree. or more, the drive cam 5
comes out of the engagement grooves 6c and 7c of the arm, so that
the arm can also be pulled out downward. Such action can also be
used to exchange arms.
First Modification Example
[0086] FIG. 6 illustrates a cam device 101 according to a first
modification example of the first embodiment. In the cam device
101, the cam devices 1 are parallelized. Specifically, it differs
from the first embodiment in that a plurality of cam disks 9 are
rotated by one rotation axis 10. In the following modification
examples and embodiments, the same parts as those in FIGS. 1A to 5E
are designated by the same reference numerals and letters and
detailed description thereof will be omitted.
[0087] In the present modification example, a plurality of drive
cams 5 reciprocally rotate about the common rotation axis 10 and a
plurality of pairs of first and second arms 6 and 7 reciprocate
linearly. The operation of each cam device 1 is the same as that of
the first embodiment.
[0088] Since a plurality of drive cams 5 can rotate at the same
time in the present modification example, the plurality of arms can
be used for carrying a plurality of works W at the same time or
carrying a long size work by gripping it with a plurality of chucks
50.
Second Modification Example
[0089] FIG. 7 illustrates a cam device 201 according to a second
modification example of the first embodiment. In the cam device
201, the cam devices 1 include multiple axes.
[0090] Specifically, the present embodiment is configured such that
drive cams 5 are simultaneously driven via a belt 112 hung on
pulleys 111 which are rotated about the rotation axes 10 and a
plurality of pairs of first and second arms 6 and 7 reciprocate
linearly.
[0091] In the present modification example, it is possible to
simultaneously control a plurality of first arms 6 and 6 or second
arms 7 and 7. Thus, for example, the plurality of first arms or
second arms can be used for simultaneous transfer of the works W to
a plurality of machine tools.
Third Modification Example
[0092] FIG. 8 illustrates a cam device 301 according to a third
modification example of the first embodiment. In the third
modification example, an outer holding cam 308 having a concentric
arcuate inner peripheral surface is further formed on the outer
side in the radial direction of the holding cam 8. The outside
holding cam 308 and the holding cam 8 are configured such that the
first arm 6 or the second arm 7 on the standby side is restricted
in vertical movement by the first restriction roller 21 or the
second restriction roller 22.
[0093] In the present modification example, since the first
restriction roller 21 and the second restriction roller 22 are
pinched by the inner peripheral surface of the outer holding cam
308 and the outer peripheral surface of the holding cam 8, the
movement of the arm on the standby side is restricted. Thus, it is
not necessary to restrict the movement of the arm on the standby
side by using its own weight. That is, there is no restriction of
placing the cam device 301 with respect to a direction of gravity.
Therefore, the movement direction of the first and second arms 6
and 7 can be horizontal direction or the like. It is also possible
to deal with a case where a reaction force is received from below
when the arm is on standby. The outer holding cam 308 is not
limited to an arcuate rib as long as the outer holding cam 308 has
an arcuate inner peripheral surface.
Second Embodiment
[0094] FIGS. 9 and 10 illustrate a cam device 401 according to a
second embodiment, which is different from the first embodiment
described above in that only one follower 407 is provided.
[0095] The embodiment is the same in that the cam device 401 for
converting the rotational movement of the drive device 13 into the
linear movement on the driven side is provided. However, in the
embodiment, only the follower 407 as one follower is provided
instead of the pair of followers. The cam device 401 includes the
holding cam 8 and the restriction roller 422 as in the first
embodiment described above.
[0096] In the embodiment, the follower 407 is arranged to be
linearly movable in the transfer direction at a position apart from
the rotation center of the drive cam 5 by a predetermined distance.
The follower 407 is configured to be cam-engaged/disengaged from
the drive cam 5, so that the holding cam 8 is separated from the
restriction roller 422 to be in the holding release state when the
drive cam 5 is in the engaged state with the follower 407.
[0097] The follower 407 forms a part of a pallet 411. The pallet
411 includes an engagement groove 418c. The engagement groove 418c
engages with the drive cam 5 as in the first embodiment described
above. As a result, the cam device 401 of this embodiment is
configured so that the pallet 411 is transferred in a feeding
direction by the drive cam 5.
[0098] Next, the operation of the cam device 401 of the present
embodiment will be described.
[0099] First, as illustrated in FIG. 9, a plurality of pallets 411
are placed on a roller conveyor 430.
[0100] When the pallet 411 moves on the roller conveyor 430 as
illustrated in FIG. 10A, the restriction roller 422 of the flowing
pallet 411 comes into contact with the arcuate outer peripheral
surface of the holding cam 8 as illustrated in FIG. 10B. Therefore,
the pallet 411 is once captured on the spot and stopped on the
roller conveyor 430.
[0101] After that, as illustrated in FIG. 10C, when the drive cam 5
fits into the engagement groove 418c, the engagement between the
restriction roller 422 and the holding cam 8 is released. By
controlling the rotation speed of the cam disk 9, the pallet 411 is
sent out while the transfer speed is adjusted.
[0102] As illustrated in FIG. 10D, the next pallet 411 can be
captured during the feeding operation of the previous pallet
411.
[0103] As described above, while the restriction roller 422 is in
contact with the outer peripheral surface of the holding cam 8, the
pallet 411 is stopped at a predetermined position, and when the
drive cam 5 is engaged, the engagement between the restriction
roller 422 and the holding cam 8 is released and the pallet 411 is
transferred in the feeding direction. This has the advantage that
one cam device 401 can cover the stopper and the separating
mechanism.
[0104] When the follower 407 is provided on only one side as in the
present embodiment, the drive cam 5 can be rotated 360.degree..
Thus, in combination with the roller conveyor 430, the drive cam 5
can be used as a separating mechanism with speed control of a
pallet transfer mechanism. While the drive cam 5 is engaged with
the engagement groove 418c of the pallet 411, the pallet 411 can be
reliably transferred in the transfer direction at a desired speed
or the like as the drive cam 5 rotates.
Modification Example
[0105] FIG. 11 illustrates a cam device 501 according to a
modification example of the second embodiment, which is different
from the second embodiment in that the cam device 501 is used as a
driving force for an external device.
[0106] In the present modification example, a follower 507 is
provided only on one side. Thus, when a restriction roller 522 of
the follower 507 is in contact with the outer peripheral surface of
the holding cam 8 and the follower 507 is waiting, the rotation of
the drive cam 5 can be used as a driving force for an external
device (not illustrated). The external device mentioned here is not
particularly limited.
Other Embodiments
[0107] The cam device may have the following configurations.
[0108] That is, although the cam device 1 is adopted to the work
supply device 3 of the vertical double disk surface grinder 2 in
the first embodiment, the cam device of the invention can be
adopted not only to a work supply device for other machine tools
including a horizontal surface grinder, but also for other
processing machines and assembling devices which perform similar
operations, or the constituent parts of these various devices.
[0109] The embodiments described above are only preferable examples
and are not intended to limit the scope of the invention, its
applications, and uses.
[0110] In accordance with an exemplary embodiment, the holding cam
for restricting the movement of the first and second followers is
provided.
[0111] In accordance with an exemplary embodiment, a cam device
converts a rotational movement of a drive unit to a linear movement
on a driven side. The cam device includes a drive cam, a pair of
first follower and second follower, a holding cam, a first
restriction roller, and a second restriction roller. The drive cam
is driven by the drive unit and reciprocally rotates in forward and
reverse directions within a predetermined angle range around a
rotation axis. The pair of first follower and second follower
intermittently reciprocate linearly by the drive cam. The holding
cam is driven rotationally integrally with a rotational
reciprocating movement of the drive cam about the rotation axis and
has an arcuate outer peripheral surface which is discontinuous on a
side facing the drive cam. The first restriction roller is provided
on the first follower and restricts a movement of the first
follower by coming in contact with the holding cam. The second
restriction roller is provided on the second follower and restricts
a movement of the second follower by coming in contact with the
holding cam. The first follower and the second follower are capable
of being cam-engaged with the driven cam alternatively and
independently of each other. The first follower and the second
follower are arranged to be capable of moving linearly at opposite
positions on both sides of a rotation center of the drive cam. When
the drive cam is in an engaged state with the first follower, the
drive cam is in an engagement release state with the second
follower and the holding cam comes into contact with the second
restriction roller to hold the second follower at a predetermined
position and the holding cam is separated from the first
restriction roller and is in a holding release state with the first
follower. When the drive cam is in an engaged state with the second
follower, the drive cam is in an engagement release state with the
first follower and the holding cam comes into contact with the
first restriction roller to hold the first follower at a
predetermined position and the holding cam is separated from the
second restriction roller and is in a holding release state with
the second follower.
[0112] According to the configuration described above, by rotating
the drive cam, the rotational movement is surely converted into the
linear movement of the first follower and the second follower. The
follower on the opposite side of the follower in the linear motion
continues to be supported at a fixed position by the holding cam.
Then, when the drive cam is in the engaged state, the corresponding
restriction roller is separated from the holding cam and is in the
holding release state, so that linear movement is possible
according to the operation of the drive cam. Therefore, it is no
longer necessary to bias the follower with the spring to hold in a
fixed position as in the related art. As a result, the number of
parts is reduced, assembly is facilitated, the energy loss
generated when compressing the spring is reduced, and the
maintenance work due to the deterioration of the spring is reduced.
It is possible to save the trouble of finely adjusting the biasing
force of the spring.
[0113] In accordance with an exemplary embodiment, the first
follower and the second follower may be configured not to be biased
in a linear movement direction by the biasing member.
[0114] According to the configuration described above, the spring
as in the related art in FIGS. 12 and 13 does not have to be
provided and the first follower and the second follower do not drop
and continue to be supported at a fixed position due to the holding
cam which supports the vertically downward force due to
gravity.
[0115] In accordance with an exemplary embodiment, an outer holding
cam having a concentric arcuate inner peripheral surface may be
further formed on an outer side in a radial direction of the
holding cam. The outer holding cam and the holding cam may be
configured so that the first follower or the second follower on the
standby side is restricted in a vertical movement by the first
restriction roller or the second restriction roller.
[0116] According to the configuration described above, the movement
of the follower on the standby side is also restricted from the
outer side in the radial direction by the inner peripheral surface
of the outer holding cam. Therefore, it is not necessary to
constrain the movement of the follower on the standby side due to
gravity. Accordingly, a setting direction of the cam device is not
constrained in the gravity direction, it would be possible to set
the movement direction of the follower to the horizontal direction
or the like.
[0117] In accordance with an exemplary embodiment, the first
follower and the second follower may include arms having work
chucks. The first follower and the second follower may be
configured to handle works gripped by the work chucks.
[0118] According to the configuration described above, the work can
be efficiently handled by using the rotational movement of the
drive cam.
[0119] In accordance with an exemplary embodiment, a plurality of
drive cams may be reciprocally rotated about the common rotation
axis and a plurality of pairs of first follower and second follower
may be linearly reciprocated.
[0120] According to the configuration described above, since a
plurality of drive cams can be rotated at the same time, the drive
cams can be used when simultaneously transferring a plurality of
works or when gripping and transferring a long work with a
plurality of chucks.
[0121] In accordance with an exemplary embodiment, a cam device
converts a rotational movement of a drive unit to a linear movement
on a driven side. The cam device includes a drive cam, a follower,
a holding cam and a restriction roller. The drive cam is driven by
the drive unit and reciprocally rotates in forward and reverse
directions within a predetermined angle range around a rotation
axis. The follower intermittently reciprocates linearly by the
drive cam. The holding cam is rotationally driven integrally with a
rotational reciprocating movement of the drive cam about the
rotation axis. The holding cam has an arcuate outer peripheral
surface which is discontinuous on a side facing the drive cam. The
restriction roller is provided on the follower and restricts a
movement of the follower by coming in contact with the holding cam.
The follower is arranged to be linearly movable at a position apart
from a rotation center of the drive cam by a predetermined
distance. The follower is configured to be cam-engaged with the
drive cam, so that the holding cam separates from the restriction
roller and is in a holding release state, when the drive cam is in
an engaged state with the follower.
[0122] According to the configuration described above, by rotating
the drive cam, the rotational movement is surely converted into the
linear movement of the follower. Then, when the drive cam is
engaged, the restriction roller is released from the holding cam
and is in the holding release state, so that linear movement is
possible according to the operation of the drive cam. Therefore, it
is possible to use the rotation of the drive cam as the driving
force of the external device during standby by setting the follower
on only one side.
[0123] In accordance with exemplary embodiment, the follower may
form a part of a pallet The pallet may be configured to be
transferred in a feeding direction by the drive cam.
[0124] According to the configuration described above, when the
follower is provided on only one side, the drive cam can be rotated
360.degree.. Thus, in combination with a roller conveyor, the drive
cam can be used as a separating mechanism with speed control of a
pallet transfer device. In particular, while the restriction roller
is in contact with the holding cam, the restriction roller is
stopped at a predetermined position, and when the drive cam is
engaged, the engagement between the restriction roller and the
holding cam is released, and thus the pallet is transferred in a
feeding direction.
[0125] In accordance with the embodiments and modification examples
described in the above, since the holding cam rotates with the
drive cam and holds the follower on the side not driven by the
drive cam, it is not necessary to provide a spring. As a result,
the cam mechanism can convert a rotational movement into a linear
movement with a simple structure.
REFERENCE SIGNS
[0126] 1, 101, 201, 301, 401, 501: cam device [0127] 2: surface
grinder [0128] 3: work supply device [0129] 5: drive cam [0130] 6:
first arm (first follower) [0131] 7: second arm (second follower)
[0132] 8: holding cam [0133] 10: rotation axis [0134] 12: device
body [0135] 13: drive device (drive unit) [0136] 21: first
restriction roller [0137] 22: second restriction roller [0138] 308:
outer holding cam [0139] 407: follower (one follower) [0140] 422:
restriction roller [0141] 430: roller conveyor [0142] 507: follower
(one follower) [0143] 522: restriction roller
* * * * *